Graphene is expected to be an enabling technology for THz antennas and related devices. This chapter describes the foundations for the theoretical and numerical modeling of graphene devices in the framework of Maxwell's equations. Subsequently, several designs of graphene planar antennas for terahertz frequencies are proposed showing that high-quality-gated graphene can be used to achieve frequency reconfiguration in resonant plasmonic antennas and beam steering in graphene-based-plasmonic reflectarrays. Afterwards, the potential of graphene for non-reciprocal applications is demonstrated experimentally, with the design, fabrication, and measurement of the first terahertz graphene isolator (operating between 1 and 10 THz). Finally, preliminary results concerning the realization of graphene beam steering reflectarray antennas at terahertz frequencies are presented. All of the above takes advantage of a newly developed theoretical “upper bound”which allows one to evaluate the closeness of a given design to the theoretical optimum, and depends uniquely on graphene conductivity.

Chapter Contents:

• 1.1 Introduction
• 1.1.1 Graphene
• 1.1.2 Outline
• 1.2 2D materials in the framework of Maxwell's equations
• 1.3 Graphene planar plasmonic antennas
• 1.3.1 Fixed frequency plasmonic antennas
• 1.3.2 Frequency-reconfigurable plasmonic antennas
• 1.3.3 Graphene plasmonic antenna model
• 1.4 Efficiency upper bounds in graphene tunable and non-reciprocal devices
• 1.4.1 Generalized electric and magnetic field representation
• 1.4.2 Demonstration of the upper bound
• 1.4.3 Graphene figure of merit
• 1.4.4 Device specific bounds
• 1.5 Graphene terahertz non-reciprocal isolator
• 1.5.1 Isolator working principle
• 1.5.2 Measurements
• 1.6 Graphene terahertz beam steering reflectarray prototype
• 1.6.1 Working principle
• 1.6.2 Design and measurement
• 1.7 Conclusions
• Acknowledgments
• References

Inspec keywords: beam steering; reflectarray antennas; plasmonics; metamaterial antennas; microwave isolators; planar antenna arrays; graphene; Maxwell equations; submillimetre wave antennas

Other keywords: resonant plasmonic antennas; high-quality-gated graphene; frequency 1.0 THz to 10.0 THz; reflectarray antennas; graphene devices; graphene beam; frequency reconfiguration; terahertz graphene isolator; Maxwell equations; graphene beam steering reflectarray antennas; planar devices; graphene conductivity; numerical modeling; terahertz frequencies; THz antennas; graphene planar antenna design; upper bound; terahertz antennas; graphene-based-plasmonic reflectarrays

Subjects: Antenna arrays; Fullerene, nanotube and related devices; Waveguide and microwave transmission line components